Battery pack structures and systems

ABSTRACT

Battery packs according to some embodiments of the present technology may include a longitudinal beam. The packs may include a plurality of battery cells disposed adjacent the longitudinal beam. Each battery cell may be characterized by a first surface, and a second surface opposite the first surface. Each battery cell may be characterized by a third surface extending vertically between the first surface and the second surface. The first surface may face the longitudinal beam, and battery terminals may extend from the third surface. Each battery cell may be characterized by a fourth surface opposite the third surface. The packs may include a lid coupled with the first surface of each battery cell of the plurality of battery cells. The packs may include a base coupled with the second surface of each battery cell of the plurality of battery cells.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. Non-Provisional patentapplication Ser. No. 17/077,259, filed Oct. 22, 2020, the disclosure ofwhich is hereby incorporated by reference in its entirety for allpurposes.

TECHNICAL FIELD

The present technology relates to battery structures and systems. Morespecifically, the present technology relates to methods of configuringand coupling batteries within a pack.

BACKGROUND

Battery placement within a battery pack may be performed with manyconsiderations. For example, battery configurations with compactplacement of battery cells may provide increased energy density byallowing more battery cells within the pack. There are many thermal,structural, and mechanical challenges with the compact placement ofcells.

SUMMARY

Battery packs according to some embodiments of the present technologymay include a longitudinal beam. The packs may include a plurality ofbattery cells disposed adjacent the longitudinal beam. Each battery cellmay be characterized by a first surface, and a second surface oppositethe first surface. Each battery cell may be characterized by a thirdsurface extending vertically between the first surface and the secondsurface. The first surface may face the longitudinal beam, and batteryterminals may extend from the third surface. Each battery cell may becharacterized by a fourth surface opposite the third surface. The packsmay include a lid coupled with the first surface of each battery cell ofthe plurality of battery cells. The packs may include a base coupledwith the second surface of each battery cell of the plurality of batterycells.

In some embodiments, the packs may include a lateral wall extending fromthe longitudinal beam between two battery cells. The plurality ofbattery cells may include a first set of battery cells and a second setof battery cells. The longitudinal beam may be characterized by a firstlongitudinal surface and a second longitudinal surface opposite thefirst longitudinal surface. The third surface of each battery cell ofthe first set of battery cells may face the first longitudinal surfaceof the longitudinal beam. The third surface of each battery cell of thesecond set of battery cells may face the second longitudinal surface ofthe longitudinal beam. The packs may include a first side beampositioned adjacent the fourth surface of each battery cell of the firstset of battery cells. The packs may include a second side beampositioned adjacent the fourth surface of each battery cell of thesecond set of battery cells.

Each battery cell of the plurality of battery cells may include a ventin the fourth surface of the battery cell. A first battery cell of theplurality of battery cells may have the vent defined in the fourthsurface proximate the first surface of the first battery cell. A secondbattery cell of the plurality of battery cells adjacent the firstbattery cell may have the vent defined in the fourth surface proximatethe second surface of the second battery cell. A side beam adjacent thefirst battery cell and the second battery cell may define a first plenumand a second plenum. The first plenum may be aligned with the vent ofthe first battery cell. The second plenum may be aligned with the ventof the second battery cell. The base may be a heat exchanger, and thebase may define fluid channels extending orthogonally to thelongitudinal beam. The longitudinal beam may be or include an I-beam.The battery terminals of each battery cell of the plurality of batterycells may extend within a recess defined within along a surface of theI-beam.

Some embodiments of the present technology may encompass battery packs.The packs may include a longitudinal beam characterized by a firstlongitudinal surface and a second longitudinal surface opposite thefirst longitudinal surface. The packs may include a first side beam. Thepacks may include a second side beam. The packs may include a pluralityof battery cells, which may include a first set of battery cellsdisposed between the first side beam and the first longitudinal surfaceof the longitudinal beam. The battery cells may include a second set ofbattery cells disposed between the second side beam and the secondlongitudinal surface of the longitudinal beam. Each battery cell of thefirst set of battery cells and each battery cell of the second set ofbattery cells may be characterized by a first surface, a second surfaceopposite the first surface, and a third surface extending verticallybetween the first surface and the second surface. The first surface mayface the longitudinal beam, and battery terminals may extend from thethird surface. The battery cells may also be characterized by a fourthsurface opposite the third surface. The packs may include a lid coupledwith the first surface of each battery cell of the plurality of batterycells. The packs may include a base coupled with the second surface ofeach battery cell of the plurality of battery cells.

In some embodiments, the packs may include a first lateral wallextending between the first side beam and the first surface of thelongitudinal beam. The first lateral wall may extend between two batterycells of the first set of battery cells. A second lateral wall mayextend between the second side beam and the second surface of thelongitudinal beam. The second lateral wall may extend between twobattery cells of the second set of battery cells. The base may be a heatexchanger, and the base may define fluid channels extending orthogonallyto the longitudinal beam. The base may define a recess within the base,and the first lateral wall may be seated within the recess definedwithin the base. The packs may include an electrical interface extendingthrough the lid and coupling with the plurality of battery cells of thebattery pack. The packs may include an electronics module seated on thelid and electrically coupled with the electrical interface. theelectronics module may be coupled with the first lateral wall.

Each battery cell of the plurality of battery cells may include a ventin the fourth surface of the battery cell. A first battery cell of thefirst set of battery cells may have the vent defined in the fourthsurface proximate the first surface of the first battery cell. A secondbattery cell of the first set of battery cells adjacent the firstbattery cell may have the vent defined in the fourth surface proximatethe second surface of the second battery cell. A first side beamadjacent the first set of battery cells may define a first plenum and asecond plenum. The first plenum may be aligned with the vent of thefirst battery cell. The second plenum may be aligned with the vent ofthe second battery cell. The battery cells may extend within at leastabout 60% of a volume of the battery pack.

Some embodiments of the present technology encompass battery packs. Thepacks may include a longitudinal beam characterized by a firstlongitudinal surface and a second longitudinal surface opposite thefirst longitudinal surface. The packs may include a plurality of batterycells including a first set of battery cells disposed adjacent the firstlongitudinal surface of the longitudinal beam. The battery cells mayinclude a second set of battery cells disposed adjacent the secondlongitudinal surface of the longitudinal beam. Each battery cell of thefirst set of battery cells and each battery cell of the second set ofbattery cells may be characterized by a first surface, a second surfaceopposite the first surface, and a third surface extending verticallybetween the first surface and the second surface. The first surface mayface the longitudinal beam, and battery terminals may extend from thethird surface. The battery cells may be characterized by a fourthsurface opposite the third surface. The packs may include a lid coupledwith the first surface of each battery cell of the plurality of batterycells. The packs may include a base coupled with the second surface ofeach battery cell of the plurality of battery cells. The base may definea plurality of heat exchange fluid channels within the base.

Such technology may provide numerous benefits over conventionaltechnology. For example, the present systems may increase volumetricenergy density over conventional pack structures. Additionally, thepresent systems may have improved component structural integrity byutilizing the battery cells as part of the support structure. These andother embodiments, along with many of their advantages and features, aredescribed in more detail in conjunction with the below description andattached figures.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of the disclosedembodiments may be realized by reference to the remaining portions ofthe specification and the drawings.

FIG. 1 shows a schematic exploded view of a battery pack according tosome embodiments of the present technology.

FIG. 2 shows a schematic partial cross-sectional view of a battery packaccording to some embodiments of the present technology.

FIG. 3 shows a schematic isometric view of a base member of a batterypack according to some embodiments of the present technology.

FIG. 4 shows a schematic partial cross-sectional view of a base memberof a battery pack according to some embodiments of the presenttechnology.

FIG. 5 shows a schematic partial view of a lid for a battery packaccording to some embodiments of the present technology.

FIG. 6 shows a schematic partial cross-sectional view of a portion of abattery pack according to some embodiments of the present technology.

FIG. 7 shows a schematic partial sectional view through a side beam of abattery pack according to some embodiments of the present technology.

Several of the figures are included as schematics. It is to beunderstood that the figures are for illustrative purposes, and are notto be considered of scale unless specifically stated to be of scale.Additionally, as schematics, the figures are provided to aidcomprehension and may not include all aspects or information compared torealistic representations, and may include exaggerated material forillustrative purposes.

In the figures, similar components and/or features may have the samenumerical reference label. Further, various components of the same typemay be distinguished by following the reference label by a letter thatdistinguishes among the similar components and/or features. If only thefirst numerical reference label is used in the specification, thedescription is applicable to any one of the similar components and/orfeatures having the same first numerical reference label irrespective ofthe letter suffix.

DETAILED DESCRIPTION

Battery packs may include any number of battery cells packaged togetherto produce an amount of power. For example, many rechargeable batteriesmay include multiple cells having any number of designs including wound,stacked, prismatic, as well as other configurations. The individualcells may be coupled together in a variety of ways including seriesconnections and parallel connections. As increased capacity is soughtfrom smaller form factors, battery cell configurations and packaging mayplay an important role in operation of the battery system under normaloperating conditions as well as during abuse conditions.

For example, cell damage may lead to short circuiting in some batterycell designs, which may cause temperature increases initiatingexothermic reactions leading to thermal runaway. These events maygenerate temperatures of several hundred degrees over a period of timethat may be seconds, minutes, or more depending on the size and capacityof the cell. Thermal runaway may occur when internal temperatures withina battery cell exceed a threshold temperature whether damage hasoccurred within the cell or not. Regardless of the initiation mechanism,once begun, the result is often continuous heat generation untilreactions have consumed the cell material. When battery cells are placedwithin a pack design, adjacent cells may be exposed to high temperaturesfrom neighboring cells undergoing failure events. Should this exposureoccur over a sufficient time period, the internal temperature within theadjacent cell may exceed the threshold for thermal runaway, extendingthe failure to the adjacent cell. This process may then continue acrosseach cell within the pack eventually consuming the majority of cells, ifnot every cell.

Conventional packs have attempted to control failure spread of thisnature by isolating cells, incorporating extensive insulation, orincreasing the separation of cells from one another. Although this mayprovide additional protection from cell failure spreading to adjacentcells, this may also limit capacity of a battery pack below some systemrequirements. Additionally, when battery packs are used in devices thatmay be dropped, impacted, pierced, or otherwise damaged, the batterypack and constituent cells may also be damaged, which may cause similarexothermic reactions to occur. Consequently, conventional technologiesmay further insulate and isolate the battery cells from a housing orstructural support, which may further reduce capacity or energy densityof the battery pack. The present technology overcomes these issues bycreating systems that incorporate the battery cells within the structureto facilitate load distribution for many different abuse events. Byincorporating the battery cells directly with the overall packstructural supports, housing and enclosure components may be reduced,which may allow increased volumetric density and specific energy for thebattery pack, which may provide a more compact and robust designcompared to conventional systems. Advantageously, by incorporatingcomponents in a space efficient manner, the present technology mayutilize less insulation due to the inherent heat spreading of couplingthe cells directly to the enclosure.

Although the remaining portions of the description will routinelyreference lithium-ion or other rechargeable batteries, it will bereadily understood by the skilled artisan that the technology is not solimited. The present techniques may be employed with any number ofbattery or energy storage devices, including other rechargeable andprimary, or non-rechargeable, battery types, as well as electrochemicalcapacitors also known as supercapacitors or ultracapacitors. Moreover,the present technology may be applicable to batteries and energy storagedevices used in any number of technologies that may include, withoutlimitation, phones and mobile devices, handheld electronic devices,laptops and other computers, appliances, heavy machinery, transportationequipment including automobiles, water-faring vessels, air-travelequipment, and space-travel equipment, as well as any other device thatmay use batteries or benefit from the discussed designs. Accordingly,the disclosure and claims are not to be considered limited to anyparticular example discussed, but can be utilized broadly with anynumber of devices that may exhibit some or all of the electrical orother characteristics of the discussed examples.

FIG. 1 shows a schematic exploded view of a battery pack 100 accordingto some embodiments of the present technology. Battery pack 100 includesa number of battery cells 105 distributed in rows along either side of alongitudinal beam 110. The battery cells 105 may be separated from oneanother by longitudinal beam 110 into two rows extending the length ofthe battery pack. In some embodiments a number of longitudinal beams maybe included within the battery pack where additional structural supportor larger form factors are produced. The longitudinal beams may providestructural integrity to the battery pack and may provide protection forbattery terminals and battery coupling as will be explained furtherbelow. As illustrated, battery pack 100 includes two sets of batterycells 105, including a first set 112 a of battery cells 105, and asecond set 112 b of battery cells 105. As shown, first set 112 a of thebattery cells may extend outward from a first longitudinal surface 111 aof the longitudinal beam 110, and second set 112 b of the battery cellsmay extend outward from a second longitudinal surface 111 b of thelongitudinal beam 110, which may be opposite the first longitudinalsurface. The battery cells 105 may be reversed in orientation betweenthe two sets as will be described further below, and which may orientthe battery terminals for all cells to be facing the longitudinal beam110.

Along surfaces of the battery cells opposite surfaces facing thelongitudinal beam may be side beams. For example, a first side beam 115may be positioned adjacent each battery cell of the first set 112 a ofthe battery cells, and a second side beam 117 may be positioned adjacenteach battery cell of the second set 112 b of the battery cells. Atintervals between battery cells may be included one or more lateralwalls 120, which may extend from the longitudinal beam 110 between twobattery cells of each set of battery cells. Any number of lateral walls120 may be included in battery packs according to the presenttechnology, which may further support each set of battery cells, andprovide additional structural integrity. The lateral walls may beincorporated at any interval of batteries, which may be equal or maydiffer across the battery pack. This may allow the lateral walls to beutilized for additional coupling as will be described below. A lid 125may be coupled overlying the battery cells, which may be seated on abase 130. In some embodiments, lid 125 may act as a structural memberproviding structural attachments to a system in which the battery packis incorporated. An electronics module 135 and power management unit maybe seated on the lid, and may be coupled with the battery cellselectronically as will be described further below.

As illustrated, battery packs according to some embodiments of thepresent technology may not include additional housing separating thebattery cells from the structural supports of the battery packs. Manyconventional battery packs may isolate the battery cells in modules thatthen may be incorporated within a structural setup for the battery pack.Because such modules may be characterized by specific geometries, theresulting battery packs may inefficiently utilize space, and maymaintain a number of gaps about the structural members. The presenttechnology may utilize alternative battery geometries and materials,which may be utilized directly with the pack structure to providefurther reinforcement of the overall battery pack, as well as for thesystem in which the battery pack may be incorporated. For example,although battery cells encompassed by the present technology may becharacterized by any dimensions, battery cells according to someembodiments of the present technology may be characterized by lateraldimensions, such as extending orthogonally to a length of longitudinalbeam 110, of greater than or about 10 cm, and may be characterized bylateral dimensions greater than or about 20 cm, greater than or about 30cm, greater than or about 40 cm, greater than or about 50 cm, greaterthan or about 60 cm, greater than or about 70 cm, greater than or about80 cm, greater than or about 90 cm, greater than or about 100 cm, ormore. Accordingly, each battery cell may extend from the longitudinalbeam 110 to an associated side beam.

In many conventional designs, insulation may be provided along all sidesof each cell block to assist in controlling heat dissipation to adjacentcells. However, because of the rapid generation of heat during failureevents, the heat transferred to adjacent cells may still be sufficientto raise internal temperatures of the adjacent cells above the thresholdto initiate thermal runaway in the adjacent cells as well. Because ofthe insulation extending around the cells, the distribution of heat tothe immediately adjacent cells may be substantially uniform, and theamount of heat generated in thermal runaway may cause internaltemperatures of each adjacent cell to increase above the thermal runawaythreshold. Consequently, many conventional designs may be limited toless compact configurations incorporating additional and thickerinsulation and module designs that incorporate more battery cellseparation.

The present technology may utilize battery cells in some embodimentsthat may be characterized by a slower reaction during failure events, orby a lower rate of degeneration of the cell materials. For example,during a failure event, reactions consuming active materials within thecell may be controlled based on the chemical makeup of the cells to slowthe reaction, which may reduce the temperature of an event.Consequently, a peak temperature during failure may be maintained belowor about 1,000° C., and may be maintained below or about 900° C., belowor about 800° C., below or about 700° C., below or about 600° C., belowor about 500° C., below or about 400° C., or lower. This may limitimpact on adjacent cells, which may otherwise be unable to survivehigher temperatures that may cause thermal runaway of adjacentbatteries. Accordingly, batteries may be spaced closer together, or withless insulation between adjacent batteries in some embodiments of thepresent technology.

By coupling the battery cells to the surrounding structural components,heat transfer from the battery cells may be further improved and lessinsulation may be incorporated within the pack, which may furtherimprove volumetric energy density. For example, in some embodiments lid125 may be coupled with a first surface of each battery cell 105utilizing a thermal interface material 140. Thermal interface material140 may directly contact each battery cell 105 of both sets or all sets,and may contact lid 125 on an opposite surface. Similarly, in someembodiments base 130 may be coupled with a second surface of eachbattery cell 105 opposite the first surface. The base 130 may be coupledwith the battery cells using a thermal interface material 145. Again,thermal interface material 145 may directly contact each battery cell105 of the battery pack, and may contact base 130 on an oppositesurface. As will be described below, base 130 may be or include a heatexchanger, and thus more direct contact between the battery cells andthe base may further facilitate heat transfer from battery cells duringoperation.

A compliant pad 150 may be positioned between each battery cell andadjacent battery cells, as well as between battery cells and lateralmembers in some embodiments of the present technology. As battery cellsare cycled during their life, the cells may swell over time as well asduring normal operation as the cell heats. When cells are rigidlycompressed or contained within a particular structure, the cells mayhave reduced cycle life. The present technology, however, may includecompliant pads or insulation configured to provide an amount ofdeflection or compression to accommodate swelling of battery cells overtime, as well as to reduce or limit heat transfer between adjacent cellblocks. The compliant pads 150 may be configured to fully occupy spacebetween each battery cell to limit any gaps within the structure.However, the thermal insulation material may be configured toaccommodate compression of up to or about 50% or more of its thicknessto accommodate battery swelling over time. Unlike conventionaltechnology that may not provide such accommodation, the presenttechnology may produce longer battery life cycles based on theincorporated accommodation of battery swelling within each cell block,and may accommodate cell thickness tolerance.

Between each side beam and the battery cells, a sealing foam 155 or padmay be incorporated, which may ensure complete seating of the side beamand the battery cells, and limit or prevent any gaps between thecomponents. End beams 160 a and 160 b may be coupled against the batterycells at longitudinal ends of the battery pack to complete the packstructure. As illustrated, the end beams 160 may be formed in halves, orsegments, which can be coupled with each set of battery cells. This mayallow a battery set to be fully formed including end beams, followed byconnecting with structural beams like longitudinal beams and side beamsof the battery pack.

The compliant pads 150 and/or sealing foam 155 may be intended to reduceheat transfer, and may be characterized by a thermal conductivity ofless than or about 0.5 W/m·K, and may be characterized by a thermalconductivity of less than or about 0.4 W/m·K, less than or about 0.3W/m·K, less than or about 0.2 W/m·K, less than or about 0.1 W/m·K, lessthan or about 0.05 W/m·K, or less. The pads may be or include any numberof insulative materials, and may include thermally resistive blankets,mats, and other materials that may include oxides of various metals, aswell as other insulative materials that may contribute to any of thethermal conductivity numbers stated. Because of the distribution of heataway from adjacent cells, the present technology may facilitate areduction in insulation between cells. For example, in some embodimentsthe amount of insulation provided between each battery cell may be lessthan or about 2 cm in thickness, and may be less than or about 1 cm,less than or about 8 mm, less than or about 6 mm, less than or about 5mm, less than or about 4 mm, less than or about 3 mm, less than or about2 mm, or less in some embodiments. The reduced insulation may contributeadditional volume in a battery pack, which may be used to incorporateadditional or larger battery cells, increasing overall capacity.

The thermal interface material 140 and/or thermal interface material 145may be intended to increase heat transfer, and may be characterized by athermal conductivity of greater than or about 0.5 W/m·K, and may becharacterized by a thermal conductivity of greater than or about 1W/m·K, greater than or about 2 W/m·K, greater than or about 5 W/m·K,greater than or about 10 W/m·K, greater than or about 25 W/m·K, orgreater. The thermal interface materials may be or include any number ofthermally conductive materials, and may include thermal pastes orgrease, polymeric, or other conductive materials. In some embodimentsthe thermal interface material may not be electrically conductive, forexample. In some embodiments because the surface of the cell block maynot be electrically charged, an electrically conductive paste, which mayalso increase thermal conductivity, may be used. Additionally, material140 and/or material 145 may be a structural adhesive in addition to oras an alternative to a thermally conductive adhesive. This may increaseoverall packaging efficiency within the pack. By utilizing the thermalinterface materials to facilitate heat transfer away from the batterycells of the battery pack, the amount of insulation utilized may bereduced as battery cell temperature may be maintained at lowertemperatures, and which again may increase the useable space within abattery pack for battery cells.

The longitudinal beams, side beams, end beams, and lateral walls, aswell as the lid and/or base, may be made of any number of materials, andmay act as structural members of the battery pack 100. Accordingly, thematerials may be or include aluminum, steel, plastic materials, orcomposite materials providing some balance between strength, rigidity,and flexibility. The longitudinal beams and lateral walls may alsoprovide an amount of heat conduction away from battery cell blocks thatare in fault or other abuse conditions, including thermal runaway. Thelongitudinal beam and lateral walls may be I-beams in some embodimentsof the present technology. While this may create recessed space alongthe length of the beams, this space may be used to accommodate aspectsof the present technology. For example, the lateral walls may seat acompliant pad within the I-beam recess, or the recesses may be sized soa height of a battery cell may be less than a height of the I-beam,which may allow adjacent battery cells to seat within the recess tolimit gaps, which may be further accommodated by a compliant pad. Thelateral walls may also provide structural attachment for auxiliarysystems as well as attachment to a device or system in which the packmay be incorporated.

Similarly, longitudinal beam 110 may include a recess on each side ofthe beam, which may accommodate aspects of the battery cells. FIG. 2shows a schematic partial cross-sectional view of a battery pack 200according to some embodiments of the present technology, and mayillustrate a cross-section extending laterally across the battery pack,such as from a first side beam to a second side beam as previouslydescribed. Battery pack 200 may include any feature, component, orcharacteristic of battery pack 100, and may illustrate additionalfeatures of battery pack 100, or other battery packs encompassed by thepresent technology. Battery pack 200 may illustrate fully coupledcomponents, which may include battery cells 205 and a longitudinal beam210 as previously described.

The battery cells 205 may be rechargeable cells, such as lithium-ionbattery cells, although any battery cells or energy storage devices maybe used in battery packs according to some embodiments of the presenttechnology. The battery cells 205 may be characterized by a number ofside surfaces depending on the geometry of the cells. FIG. 2 illustratesrectangular cells within battery pack 200, although other geometries andconfigurations are also encompassed. As illustrated, each battery cell205 may be characterized by side surfaces in reference to thelongitudinal beam 210. For example, the battery cell may becharacterized by a first side surface 206 adjacent a lid of the batterypack. A thermal interface material may couple each battery cell with thelid as previously described. This may allow each cell to be included asan additional structural member of the pack. For example, unlike manyconventional technologies that may fully separate the cells fromsurrounding structural members, the present technology may reinforce thepack further by incorporating the battery cells as structural componentsof the pack. Battery cell 205 may be characterized by a second sidesurface 207 opposite the first side surface 206. Second side surface 207may be adjacent the base of the battery pack 200, and a thermalinterface material may couple each battery cell with the base of thebattery pack as previously described. Battery cell 205 may becharacterized by a third side surface 208 extending vertically betweenthe first side surface and the second side surface. Third side surface208 of each battery cell may face the longitudinal beam 210, and thusbattery cells of a first set 212 a of cells and battery cells of asecond set 212 b of cells may be reversed in orientation so a third sideof each cell for each set faces the longitudinal beam 210. Battery cell205 may further be characterized by a fourth side surface 209 oppositethe third surface 208.

Battery pack 200 may include a first side beam 215 adjacent the firstset of battery cells, and may include a second side beam 217 adjacentthe second set of battery cells. As illustrated, each side beam maydefine one or more plenums within the side beam. As one non-limitingexample, side beam 215 may illustrate a first plenum 220 and a secondplenum 222 defined within the side beam. Each battery cell may include avent 224 formed in fourth surface 209 of the cell, which may allowvented effluents to be exhausted from the vent and into the plenumdefined within the side beam. As will be described further below,adjacent battery cells may alternate vertical location of the vent,similar to cell 205 a and cell 205 b. For example, battery cell 205 amay include a vent 224 a formed within the fourth surface of the batterycell proximate second surface 207 as illustrated, and which may be inline with second plenum 222 formed in the side beam. Additionally,battery cell 205 b may include a vent 224 b formed within the fourthsurface of the battery cell proximate first surface 206 as illustrated,and which may be in line with first plenum 220 formed in the side beam.By alternating vent locations between adjacent batteries, a lower heatimpact may be provided to adjacent battery cells during a particularabuse event. The first plenum and the second plenum may be fluidlyisolated from one another by a cross-member in the side beam asillustrated, which may further limit impact if two adjacent batteriesexhaust heated effluent materials by separating the materials from oneanother within the side beam.

Battery pack 200 may also include a lid 225 coupled with first surfaces206 of the battery cells as previously described, and which may operateas a structural member of the pack in addition to operating as a sealingmember. Additionally, battery pack 200 may include a base 230 coupledwith second surfaces 207 of the battery cells as previously described.As noted above, base 230 may be or include a heat exchanger forfacilitating heat transfer from the battery cells during operation. Forexample, base 230 may define one or more fluid channels 232 extendingorthogonally to a length of the longitudinal beam 210. Through each sidebeam, an inlet/outlet port 235 may extend from the base member fordelivering or retrieving a heat transfer fluid that may be flowed withinthe channels. As will be described below, the inlet/outlet port 235 mayflow the heat transfer fluid longitudinally along a flow path throughthe battery pack, and through fluid channels 232, which may then directthe heat transfer fluid along a flow path at the opposite side beambefore retrieving the heat transfer fluid at the other inlet/outletport.

In some embodiments of the present technology, lid 225 may also be orinclude a similar heat exchanger or define similar fluid channels, whichmay be utilized with the base heat exchanger to further improve heattransfer through the battery pack. Additionally, the lid heat exchangerwhen incorporated, may receive fluid from the base heat exchanger, orvice versa, and may deliver the heat transfer fluid back across thefirst surface of the battery cells through fluid channels defined in thelid, for example. The heat transfer fluid may be directed in an oppositedirection as within the base, which may reduce a temperature gradientacross the battery pack caused by flow of the fluid in a singledirection through the base. Additionally or alternatively, in someembodiments a pump or delivery system for the heat transfer fluid mayreverse flow at regular intervals, to limit or reduce a gradient acrossthe battery pack.

Battery pack 200 also illustrates an embodiment where longitudinal beam210 is an I-beam. As discussed previously, battery terminals 240 mayextend from third surface 208 of each battery cell towards thelongitudinal beam 210. Battery terminals may limit how flush the batterycells may be incorporated with the longitudinal beam. However, becausethe I-beam structure may provide recesses defined on each side of thebeam, the battery terminals may be positioned within the recess, whichmay allow the battery cells to be more tightly packaged within thebattery pack. Busbars may extend adjacent the longitudinal beam and mayextend the length of the battery pack coupling each battery set inseries, although parallel configurations may similarly be encompassed.The battery sets of the battery pack may then be coupled together inseries to increase the voltage of the battery pack, or in parallel toincrease the energy density at a set voltage. As will be describedbelow, the electrical coupling may extend through the lid 225 or throughan end of the pack.

By limiting the components and insulation of the battery pack asdescribed, by utilizing the battery cells as part of the structuralsetup of the battery pack, and by reducing the tolerances betweencomponents as shown, a volumetric energy density and specific energy ofthe battery pack may be improved over conventional technologies byincreasing the volume of the pack associated with the battery cells. Forexample, in some embodiments of the present technology, the batterycells may account for greater than or about 50% of the volume of thebattery pack, and may account for greater than or about 55% of thevolume of the battery pack, greater than or about 60% of the volume ofthe battery pack, greater than or about 65% of the volume of the batterypack, greater than or about 70% of the volume of the battery pack,greater than or about 75% of the volume of the battery pack, greaterthan or about 80% of the volume of the battery pack, or more. This mayallow smaller battery packs to be utilized in electronic devices andmachines, and may reduce weight associated with the battery packs.

FIG. 3 shows a schematic isometric view of a base member 300 that may beused in battery packs according to some embodiments of the presenttechnology. Base member 300 may be included with battery packs describedelsewhere in the present disclosure, and may illustrate additionalfeatures of base members according to some embodiments of the presenttechnology. Base member 300 may include one or more sections that may bebonded, welded, or otherwise coupled together to form the base member.Each section may be extruded or otherwise formed to provide fluidchannels extending across the base member. Each channel may be fluidlyisolated within the base to control fluid flow within the base, andmaintain a heat transfer fluid isolated from the battery cells. Amongthe fluid channels, the base member 300 may define one or more recesses305. These recesses may seat the lateral walls between battery cells,which may allow the cells to seat flush against the base, or against athermal interface material coupled between the base and each batterycell as previously described. Base member 300 may operate as both a heatexchanger as well as an external support and protective member for thebattery pack based on the materials and configuration. By combiningthese features into a single component, further space savings may beprovided.

As illustrated, base member 300 may include inlet/outlet ports 310 fordelivering and retrieving the heat transfer fluid from the base member300. A manifold 315, removed from the base member for ease of viewing,may define a channel 318 extending along the manifold, and which maydeliver the heat transfer fluid along a length of the base member. Asillustrated, the manifold channel 318 may increase in volume or widthalong the length, and the opposite manifold may have a reverse channelformed. These channels may cooperate to produce a more equal conductanceof heat transfer fluid at each fluid channel through the base memberalong a longitude of the base member, which may facilitate more uniformheat transfer from each battery cell of the battery pack.

FIG. 4 shows a schematic partial cross-sectional view of base member 300for use in a battery pack according to some embodiments of the presenttechnology, and may illustrate additional features of base member 300and fluid channels extending through the base member. As illustrated,fluid channels 405 may be formed within the base member. In someembodiments the fluid channels 405 may be formed integrally with thebase member sections, which may be extruded metal. Accordingly, thechannels may each be fluidly isolated from each other and from thebattery cells that may be seated on the base member, or coupled with thebase member with a thermal interface material. Recesses 305 aspreviously described may be formed between fluid channels 405.Accordingly, lateral walls may be seated within the recesses 305, whilemaintaining fluid isolation within the channels 405 formed within thebase member. This formation of isolated channels may also increase apressure threshold that the heat exchanger may withstand. Consequently,in some embodiments heat transfer fluids that may be used in the systemmay include aqueous fluids, such as may include glycol or othermaterials, as well as refrigerant that may be maintained under pressurewithin the base member and an associated refrigerant loop.

FIG. 5 shows a schematic partial view of a lid 500 for a battery packaccording to some embodiments of the present technology. As describedpreviously, a power module, or electronics module may be seated on thelid in some embodiments of the present technology. The lid may define anaccess through which an electrical interface 505 may extend. Electricalinterface 505 may include one or more connectors providing electricalcoupling for access to the battery cells. The lid may include a boss 510projecting from the lid and extending about the electrical interface505. The boss may include an environmental seal to limit intrusion intothe pack structure. The connectors may include one or more high-voltagebus connections, which may provide electrical coupling with theindividual battery cells, as well as any other power or sensorconnections for the battery cells.

FIG. 6 shows a schematic partial cross-sectional view of a portion of abattery pack 600 according to some embodiments of the presenttechnology, and may illustrate a cross-section extending longitudinallyacross a portion of the battery pack, such as through a number ofbattery cells and lateral walls. Battery pack 600 may include anyfeature, component, or characteristic of battery packs describedpreviously, and may illustrate additional features of any battery packdescribed elsewhere, or other battery packs encompassed by the presenttechnology. Battery pack 600 may illustrate fully coupled components,which may include battery cells 605 as previously described. Batterypack 600 may include a lid 610, which may be coupled with a firstsurface of the battery cells as previously described. Similarly, batterypack 600 may include a base 615, which may define a plurality of fluidchannels for delivering a heat exchange fluid as discussed above.

Battery pack 600 may include one or more lateral walls 620 as previouslydescribed, which may extend at intervals between battery cells. Asdiscussed above, lateral walls 620 may seat within the base 615 atrecesses 618, which may allow battery cells 605 to be disposed in closercontact with the base member or a thermal interface material couplingthe battery cells with the base. Some lateral walls 620 may also includean interface 622 or receptacle that may extend through lid 610 asillustrated. The interfaces may allow mechanical coupling of components,such as an electronics module 625. The interfaces may further be used tocouple the battery pack within a surrounding structure, which mayfurther improve pack stiffness and reinforcement. As illustrated, theelectronics module may be seated on the lid of the battery pack, and maycouple with connectors extending through the lid as previouslydescribed. To limit movement of the electronics module, the module maybe coupled with the lateral walls utilizing the interfaces 622. Theelectronics module may include electrical connections with the batterycells, and may include additional monitoring, sensing, and controlcomponents associated with the battery pack operation.

FIG. 7 shows a schematic partial sectional view through a side beam of abattery pack 700 according to some embodiments of the presenttechnology, and may illustrate a cross-section extending longitudinallyacross a portion of the battery pack, such as along a side beam. Batterypack 700 may include any feature, component, or characteristic ofbattery packs described previously, and may illustrate additionalfeatures of any battery pack described elsewhere, or other battery packsencompassed by the present technology. Battery pack 700 may illustrateadditional features of a plenum structure formed within the side beamsaccording to some embodiments. For example, side beam 705 may define afirst plenum 710 and a second plenum 715, which may be fluidly separatedalong the side beam with a divider 720. The plenums may be formedadjacent vents of the battery cells. As noted previously, each batterycell may have the vent formed at an alternating location from adjacentbattery cells. For example, while a first battery cell includes a ventnear the lid, which may exhaust into the first plenum 710, an adjacentbattery cell may include a vent near the base, which may exhaust intothe second plenum 715. These separate venting plenums may limitinteraction of effluent materials with adjacent batteries. The plenumsmay extend to a pack vent located at an end beam or integrated into aside beam, which may allow any effluent materials to leave the batterypack. By utilizing structural components and configurations according toembodiments of the present technology, battery packs may be producedhaving improved structural integrity, while limiting increases in volumedue to additional packaging and insulation materials.

In the preceding description, for the purposes of explanation, numerousdetails have been set forth in order to provide an understanding ofvarious embodiments of the present technology. It will be apparent toone skilled in the art, however, that certain embodiments may bepracticed without some of these details, or with additional details.

Having disclosed several embodiments, it will be recognized by those ofskill in the art that various modifications, alternative constructions,and equivalents may be used without departing from the spirit of theembodiments. Additionally, a number of well-known processes and elementshave not been described in order to avoid unnecessarily obscuring thepresent technology. Accordingly, the above description should not betaken as limiting the scope of the technology.

Where a range of values is provided, it is understood that eachintervening value, to the smallest fraction of the unit of the lowerlimit, unless the context clearly dictates otherwise, between the upperand lower limits of that range is also specifically disclosed. Anynarrower range between any stated values or unstated intervening valuesin a stated range and any other stated or intervening value in thatstated range is encompassed. The upper and lower limits of those smallerranges may independently be included or excluded in the range, and eachrange where either, neither, or both limits are included in the smallerranges is also encompassed within the technology, subject to anyspecifically excluded limit in the stated range. Where the stated rangeincludes one or both of the limits, ranges excluding either or both ofthose included limits are also included. Where multiple values areprovided in a list, any range encompassing or based on any of thosevalues is similarly specifically disclosed.

As used herein and in the appended claims, the singular forms “a”, “an”,and “the” include plural references unless the context clearly dictatesotherwise. Thus, for example, reference to “a material” includes aplurality of such materials, and reference to “the cell” includesreference to one or more cells and equivalents thereof known to thoseskilled in the art, and so forth.

Also, the words “comprise(s)”, “comprising”, “contain(s)”, “containing”,“include(s)”, and “including”, when used in this specification and inthe following claims, are intended to specify the presence of statedfeatures, integers, components, or operations, but they do not precludethe presence or addition of one or more other features, integers,components, operations, acts, or groups.

What is claimed is:
 1. A battery pack comprising: an enclosure having atleast four sidewalls connected to a base, wherein one or more componentsof the enclosure are extruded; and a plurality of cells arranged in oneor more rows and disposed on the base, wherein each cell of theplurality of cells has a large wall surface and a small wall surface,and wherein a surface area of the small wall surface is less than asurface area of the large wall surface; wherein, for each row of the oneor more rows, the plurality of cells are arranged such that their largewall surfaces are parallel to each other.
 2. The battery pack of claim1, wherein two sidewalls of the at least four sidewalls are end platesthat are arranged parallel to the large wall surfaces with one of thetwo sidewalls being adaptable to apply a compressive force to theplurality of cells.
 3. The battery pack of claim 1, wherein the at leastfour sidewalls are mechanically attached to the base.
 4. The batterypack of claim 1, wherein the enclosure comprises an electronicscompartment that houses one or more battery pack electronics controlmodules.
 5. The battery pack of claim 4, wherein the battery packelectronic control modules include one or more of a Battery EnergyControl Module (BECM), a sensor module or a high voltage connector. 6.The battery pack of claim 1, wherein the base is an extrusion thatcomprises a plurality of fluid channels configured to cool the batterypack, wherein the plurality of fluid channels extend along a length ofthe base.
 7. The battery pack of claim 6, wherein the plurality of fluidchannels have a substantially rectangular profile.
 8. The battery packof claim 6, wherein the base defines a recess extending from a topsurface of the base to a depth of the plurality of fluid channels. 9.The battery pack of claim 1, wherein at least 70 percent of a volume ofthe battery pack is occupied by cells.
 10. The battery pack of claim 1,wherein each row of the one or more rows has a same number of cells. 11.The battery pack of claim 1, wherein the battery pack has at least tworows and each row is separated from an adjacent row by a divider. 12.The battery pack of claim 1, wherein two other sidewalls of the at leastfour sidewalls are arranged opposite each other along a plane of thesmall wall surface to confine to the plurality of cells.
 13. The batterypack of claim 1, further comprising one or more busbars connected to theplurality of cells through electrical connectors.
 14. A battery packcomprising: an enclosure having at least four sidewalls connected by abase, the base being an extrusion; and a first endplate that forms oneof said at least four sidewalls, the first endplate configured to bewelded or attached to the base to apply compressive load to a pluralityof cells; wherein a body of the enclosure is made from extruded partsand the at least four sidewalls are mechanically attached or welded tothe base.
 15. The battery pack of claim 14, wherein the enclosurecomprises an electronics compartment that houses one or more batterypack electronics control modules.
 16. The battery pack of claim 14,wherein at least 70 percent of a volume of the battery pack is occupiedby cells.
 17. A method for producing a battery pack, the methodcomprising: forming an enclosure that includes a base and at least foursidewalls, wherein the base is formed by extrusion to include aplurality of fluid channels; providing a plurality of cells with each ofthe plurality of cells having a large wall surface and a small wallsurface, a surface area of the small wall surface being less than asurface area of the large wall surface; arranging the plurality of cellson the base such that their large wall surfaces are parallel to eachother; and retaining the plurality of cells under compression betweentwo sidewalls of the at least four sidewalls, wherein the compression isin a direction perpendicular to the large wall surfaces; wherein atleast one sidewall of the at least four sidewalls is mechanicallyattached to the base.
 18. The method of claim 17, further comprising:creating a pressure differential, by a pump, to move a cooling liquidthrough the plurality of fluid channels to cool the plurality of cells.19. The method of claim 17, further comprising: forming, as part of theenclosure, an electronics compartment disposed on a second end of thebattery pack to house one or more battery pack electronics controlmodules.
 20. The method of claim 17, further comprising forming theenclosure and arranging the plurality of cells on the base of theenclosure such that at least 70% of a volume of the battery pack isoccupied by the plurality of cells.